Despite recent advances in HIV prevention, injecting drug users (IDUs) in the U.S. still account for 1/3 of new infections. Racial/ethnic disparities in injection drug use also continue to cause a disproportionate share of new HIV cases among minorities and women. This proposal targets a vulnerable and understudied population of IDUs - minority, heterosexual, IDU couples (i.e. partnered IDUs). While research on partnered IDUs is scarce, existing literature indicates that partnered IDUs are at high risk for HIV from both drug- related and sexual risk behaviors. Partnered IDUs, especially partnered women IDUs, also have limited success in reducing drug use, accessing or completing drug abuse treatment, and maintaining treatment outcomes (reduced drug use, safer drug-use practices, safer sex). This profile of partnered IDUs has important implications for treatment-based HIV prevention. Drug abuse treatment is an effective method for reducing drug-and sex-related HIV risk among IDUs. A recent NIDA publication concludes that "drug abuse treatment is HIV prevention." However, the median proportion of IDUs who access treatment in the U.S. is extremely low - less than 9%. Clearly, the full efficacy of HIV prevention cannot be realized unless more IDUs enter treatment. Since a substantial number of IDUs are sexually partnered with other IDUs (more than 40%, according to out own NYC data), understanding and overcoming barriers to successful treatment and treatment-based HIV prevention among partnered IDUs will have a substantial impact on reducing drug use and HIV risk, especially among minority women. This qualitative study of IDU couples and treatment providers focuses on two sets of barriers to drug treatment and treatment-based HIV risk reduction among African American and Latino heterosexual IDU couples in NYC: (1) relationship dynamics among partnered IDUs that deter treatment entry, retention or the maintenance of outcomes; and (2) couples-specific structural barriers in the treatment system that further inhibit treatment entry, retention, and the maintenance of outcomes. We are also interested in (3) how these two kinds of barriers interact. Findings from the proposed research will inform subsequent work to quantify these barriers and develop and evaluate programs to overcome them. This study is proposed by a new investigator and utilizes the R-21 mechanism. PUBLIC HEALTH STATEMENT HIV transmission among injection drug users (IDUs) continues to be an important public health issue. Despite recent advances in HIV prevention, injection drug users in the U.S. still account for 1/3 of all new infections. Racial/ethnic disparities in injection drug use also continue to cause a disproportionate share of infections. The proposed study primarily targets African American and Latino IDUs who are partnered in intimate relationships. While research on partnered IDUs is scarce, existing literature indicates that they are at high risk for HIV from both drug-related and sexual risk behaviors. In addition, they have limited success in reducing drug use, accessing or completing drug abuse treatment and maintaining treatment outcomes (reduced drug use, safer drug use practices, safer sex). The proposed study will contribute to an understanding of interpersonal and structural barriers to drug treatment and treatment-mediated HIV prevention and lead to recommendations for needed improvements. [unreadable] [unreadable] [unreadable]